<?php
/**
 * Zend Framework
 *
 * LICENSE
 *
 * This source file is subject to the new BSD license that is bundled
 * with this package in the file LICENSE.txt.
 * It is also available through the world-wide-web at this URL:
 * http://framework.zend.com/license/new-bsd
 * If you did not receive a copy of the license and are unable to
 * obtain it through the world-wide-web, please send an email
 * to license@zend.com so we can send you a copy immediately.
 *
 * @category   Zend
 * @package    Zend_Db
 * @subpackage Statement
 * @copyright  Copyright (c) 2005-2009 Zend Technologies USA Inc. (http://www.zend.com)
 * @license    http://framework.zend.com/license/new-bsd     New BSD License
 * @version    $Id: Db2.php 18951 2009-11-12 16:26:19Z alexander $
 */

/**
 * @see Zend_Db_Statement
 */
require_once 'Zend/Db/Statement.php';

/**
 * Extends for DB2 native adapter.
 *
 * @package    Zend_Db
 * @subpackage Statement
 * @copyright  Copyright (c) 2005-2009 Zend Technologies USA Inc. (http://www.zend.com)
 * @license    http://framework.zend.com/license/new-bsd     New BSD License
 */
class Zend_Db_Statement_Db2 extends Zend_Db_Statement
{

	/**
	 * Column names.
	 */
	protected $_keys;

	/**
	 * Fetched result values.
	 */
	protected $_values;

	/**
	 * Prepare a statement handle.
	 *
	 * @param string $sql
	 * @return void
	 * @throws Zend_Db_Statement_Db2_Exception
	 */
	public function _prepare($sql)
	{
		$connection = $this->_adapter->getConnection();

		// db2_prepare on i5 emits errors, these need to be
		// suppressed so that proper exceptions can be thrown
		$this->_stmt = @db2_prepare($connection, $sql);

		if (!$this->_stmt) {
			/**
			 * @see Zend_Db_Statement_Db2_Exception
			 */
			require_once 'Zend/Db/Statement/Db2/Exception.php';
			throw new Zend_Db_Statement_Db2_Exception(
			db2_stmt_errormsg(),
			db2_stmt_error()
			);
		}
	}

	/**
	 * Binds a parameter to the specified variable name.
	 *
	 * @param mixed $parameter Name the parameter, either integer or string.
	 * @param mixed $variable  Reference to PHP variable containing the value.
	 * @param mixed $type      OPTIONAL Datatype of SQL parameter.
	 * @param mixed $length    OPTIONAL Length of SQL parameter.
	 * @param mixed $options   OPTIONAL Other options.
	 * @return bool
	 * @throws Zend_Db_Statement_Db2_Exception
	 */
	public function _bindParam($parameter, &$variable, $type = null, $length = null, $options = null)
	{
		if ($type === null) {
			$type = DB2_PARAM_IN;
		}

		if (isset($options['data-type'])) {
			$datatype = $options['data-type'];
		} else {
			$datatype = DB2_CHAR;
		}

		if (!db2_bind_param($this->_stmt, $position, "variable", $type, $datatype)) {
			/**
			 * @see Zend_Db_Statement_Db2_Exception
			 */
			require_once 'Zend/Db/Statement/Db2/Exception.php';
			throw new Zend_Db_Statement_Db2_Exception(
			db2_stmt_errormsg(),
			db2_stmt_error()
			);
		}

		return true;
	}

	/**
	 * Closes the cursor, allowing the statement to be executed again.
	 *
	 * @return bool
	 */
	public function closeCursor()
	{
		if (!$this->_stmt) {
			return false;
		}
		db2_free_stmt($this->_stmt);
		$this->_stmt = false;
		return true;
	}


	/**
	 * Returns the number of columns in the result set.
	 * Returns null if the statement has no result set metadata.
	 *
	 * @return int The number of columns.
	 */
	public function columnCount()
	{
		if (!$this->_stmt) {
			return false;
		}
		return db2_num_fields($this->_stmt);
	}

	/**
	 * Retrieves the error code, if any, associated with the last operation on
	 * the statement handle.
	 *
	 * @return string error code.
	 */
	public function errorCode()
	{
		if (!$this->_stmt) {
			return false;
		}

		$error = db2_stmt_error();
		if ($error === '') {
			return false;
		}

		return $error;
	}

	/**
	 * Retrieves an array of error information, if any, associated with the
	 * last operation on the statement handle.
	 *
	 * @return array
	 */
	public function errorInfo()
	{
		$error = $this->errorCode();
		if ($error === false){
			return false;
		}

		/*
		 * Return three-valued array like PDO.  But DB2 does not distinguish
		 * between SQLCODE and native RDBMS error code, so repeat the SQLCODE.
		 */
		return array(
		$error,
		$error,
		db2_stmt_errormsg()
		);
	}

	/**
	 * Executes a prepared statement.
	 *
	 * @param array $params OPTIONAL Values to bind to parameter placeholders.
	 * @return bool
	 * @throws Zend_Db_Statement_Db2_Exception
	 */
	public function _execute(array $params = null)
	{
		if (!$this->_stmt) {
			return false;
		}

		$retval = true;
		if ($params !== null) {
			$retval = @db2_execute($this->_stmt, $params);
		} else {
			$retval = @db2_execute($this->_stmt);
		}

		if ($retval === false) {
			/**
			 * @see Zend_Db_Statement_Db2_Exception
			 */
			require_once 'Zend/Db/Statement/Db2/Exception.php';
			throw new Zend_Db_Statement_Db2_Exception(
			db2_stmt_errormsg(),
			db2_stmt_error());
		}

		$this->_keys = array();
		if ($field_num = $this->columnCount()) {
			for ($i = 0; $i < $field_num; $i++) {
				$name = db2_field_name($this->_stmt, $i);
				$this->_keys[] = $name;
			}
		}

		$this->_values = array();
		if ($this->_keys) {
			$this->_values = array_fill(0, count($this->_keys), null);
		}

		return $retval;
	}

	/**
	 * Fetches a row from the result set.
	 *
	 * @param int $style  OPTIONAL Fetch mode for this fetch operation.
	 * @param int $cursor OPTIONAL Absolute, relative, or other.
	 * @param int $offset OPTIONAL Number for absolute or relative cursors.
	 * @return mixed Array, object, or scalar depending on fetch mode.
	 * @throws Zend_Db_Statement_Db2_Exception
	 */
	public function fetch($style = null, $cursor = null, $offset = null)
	{
		if (!$this->_stmt) {
			return false;
		}

		if ($style === null) {
			$style = $this->_fetchMode;
		}

		switch ($style) {
			case Zend_Db::FETCH_NUM :
				$row = db2_fetch_array($this->_stmt);
				break;
			case Zend_Db::FETCH_ASSOC :
				$row = db2_fetch_assoc($this->_stmt);
				break;
			case Zend_Db::FETCH_BOTH :
				$row = db2_fetch_both($this->_stmt);
				break;
			case Zend_Db::FETCH_OBJ :
				$row = db2_fetch_object($this->_stmt);
				break;
			case Zend_Db::FETCH_BOUND:
				$row = db2_fetch_both($this->_stmt);
				if ($row !== false) {
					return $this->_fetchBound($row);
				}
				break;
			default:
				/**
				 * @see Zend_Db_Statement_Db2_Exception
				 */
				require_once 'Zend/Db/Statement/Db2/Exception.php';
				throw new Zend_Db_Statement_Db2_Exception("Invalid fetch mode '$style' specified");
				break;
		}

		return $row;
	}

	/**
	 * Fetches the next row and returns it as an object.
	 *
	 * @param string $class  OPTIONAL Name of the class to create.
	 * @param array  $config OPTIONAL Constructor arguments for the class.
	 * @return mixed One object instance of the specified class.
	 */
	public function fetchObject($class = 'stdClass', array $config = array())
	{
		$obj = $this->fetch(Zend_Db::FETCH_OBJ);
		return $obj;
	}

	/**
	 * Retrieves the next rowset (result set) for a SQL statement that has
	 * multiple result sets.  An example is a stored procedure that returns
	 * the results of multiple queries.
	 *
	 * @return bool
	 * @throws Zend_Db_Statement_Db2_Exception
	 */
	public function nextRowset()
	{
		/**
		 * @see Zend_Db_Statement_Db2_Exception
		 */
		require_once 'Zend/Db/Statement/Db2/Exception.php';
		throw new Zend_Db_Statement_Db2_Exception(__FUNCTION__ . '() is not implemented');
	}

	/**
	 * Returns the number of rows affected by the execution of the
	 * last INSERT, DELETE, or UPDATE statement executed by this
	 * statement object.
	 *
	 * @return int     The number of rows affected.
	 */
	public function rowCount()
	{
		if (!$this->_stmt) {
			return false;
		}

		$num = @db2_num_rows($this->_stmt);

		if ($num === false) {
			return 0;
		}

		return $num;
	}

	/**
	 * Returns an array containing all of the result set rows.
	 *
	 * @param int $style OPTIONAL Fetch mode.
	 * @param int $col   OPTIONAL Column number, if fetch mode is by column.
	 * @return array Collection of rows, each in a format by the fetch mode.
	 *
	 * Behaves like parent, but if limit()
	 * is used, the final result removes the extra column
	 * 'zend_db_rownum'
	 */
	public function fetchAll($style = null, $col = null)
	{
		$data = parent::fetchAll($style, $col);
		$results = array();
		$remove = $this->_adapter->foldCase('ZEND_DB_ROWNUM');

		foreach ($data as $row) {
			if (is_array($row) && array_key_exists($remove, $row)) {
				unset($row[$remove]);
			}
			$results[] = $row;
		}
		return $results;
	}
}
